Data from Phases 1 and 2 of the Third National Health and Nutrition Examination Survey (NHANES III) is available for about 15,000 dentate individuals 13 years of age and older. The examination involved assessment of periodontal health including measurement of tooth loss, attachment loss, pocket depths, gingival recession, gingival inflammation, and dental calculus. This material will be used to assess the prevalence of periodontal disease in the United States. The results may be useful for evaluating the dynamics of the oral health of the U.S. adults, and can be valuable for planning the periodontal treatment need in the population.